The aim of this proposal is to examine the involvement of defensins, a family of antibacterial peptides, in the etiology of acne. Acne is an inflammation of the pilosebaceous duct in the skin and afflicts a great number of adolescents, male and female, until early adulthood. The cause of acne is believed to be an increased sebum production, followed by colonization of the pilosebaceous duct by bacteria and an inflammatory reaction to the bacteria. While circulating androgens have been identified as a factor contributing to acne, they cannot be the only factor. The purpose of this proposal is to explore a different approach to studying acne, which, somewhat surprisingly, has not yet been mentioned in the1iterature. There is a growing awareness of the role of defensins and possibly other antibacterial peptides in the overall defense of the immune system against microbial invaders. The proposed experiments serve to examine the production of defensins in the sebaceous gland, with the goal of determining to which extent defensin levels may differ in normal skin and in acne. A long-term goal would be to find a method to enhance the production of endogenous defensins (or prevent their potential downregulation), or to treat the infected tissue with exogenous defensins.